STRAUSS:  Also sprach Zarathustra, Op. 30.  Alpine Symphony, Op. 64
Dresden Staatskapelle/Rudolf Kempe, cond.
EMI CLASSICS DVDA 923969 TT:  82:47
(4 channel)
Both of these heavily-scored symphonic poems should be sonic showpieces but here they are not.  Recorded in 1971, these were early EMI attempts as multi-channel sound, but they are not impressive.    Deficient in low bass (so important in Zarathustra), and with overly-harsh highs, these do not impress, in spite of the superb performances by a master Strauss conductor.
MAHLER:  Symphony No. 10 (Cooke edition)
Berlin Philharmonic Orch/Sir Simon Rattle, cond.
EMI CLASSICS DVDA 923949 TT: 77:23
(5.1 channel)

A memorable performance (see RD's REVIEW).  Perhaps because of being recorded live, microphones are very close - and there is little Philharmonie resonance, which means steely strings, limited low bass, and a stark audio representation of the famed Berlin Philharmonic under Sir Simon just before he became music director of the orchestra.